Target Audience:

Who should attend:

• Clinical faculty from the University of Pittsburgh School of Pharmacy
• Clinical staff pharmacists employed by the University of Pittsburgh Medical Center and deployed throughout the hospital campus in unit based roles and centrally in the department of pharmacy's main pharmacy
• Student pharmacy interns currently working within the department of pharmacy
• Certified Pharmacy Technicians

Abstract
Heparin Induced Thrombocytopenia (HIT) is an immune associated thrombocytopenia that promotes a prothrombotic state and occurs in 1-3% of patients receiving unfractionated heparin (UFH). The incidence of HIT increases to 10.6% in patients requiring mechanical circulatory support (MCS). Although the incidence of HIT is greater in this patient population, many factors can make identifying HIT difficult. These factors include device related thrombocytopenia, ineffective HIT screening tools, and discordant HIT laboratory assays.

UFH is the anticoagulant of choice for patients requiring extracorporeal membrane oxygenation (ECMO) and is the purge anticoagulant of choice for patients requiring Impellas (Abiomed, Danvers, MA). Due to the higher incidence of HIT in this patient population and the inability to effectively screen for HIT, patients are at risk for devastating thrombotic complications as well as delays in obtaining a transplant or durable ventricular assist device (VAD). Alternative anticoagulation strategies utilizing direct thrombin inhibitors such as bivalirudin or argatroban will most likely become necessary if UFH is given in this patient population, but data supporting the use of alternative anticoagulants are limited. This presentation outlines the screening and diagnosis of HIT in patients requiring ECMO or Impellas as well as the evidence to support utilizing alternative anticoagulation strategies instead of UFH as first line.

Educational Objectives:

Upon successful completion of this continuing pharmacy education program, the participant should be able to:

• Describe the incidence and pathophysiology of HIT.
• Recognize the barriers to identifying HIT in patients requiring mechanical circulatory support.
• Discuss the evidence surrounding alternative anticoagulation strategies for HIT in patients with mechanical circulatory support devices.

Pharmacy Continuing Education Credits This program is sponsored by the University of Pittsburgh Center for Continuing Education in the Health Sciences. The University of Pittsburgh Center for Continuing Education in the Health Sciences is accredited by the Accreditation Council for Pharmacy Education (ACPE) as a Provider of continuing pharmacy education. The assigned universal program number(s) is JA4008223-0000-23-066-H01-P. This module is a webcast of an ACPE approved live presentation. The minimum credit awarded for this module (.75 contact hour) is determined by the length of the entire live presentation inclusive of the post-test.

Suggested Additional Reading:

1. Abiomed, Inc: Impella ventricular support systems for use dur- ing cardiogenic shock. Impella 2.5, 5.0, LD and Impella CP Instructions for Use and Clinical Reference Manual. Danvers, MA, Abiomed, 2016.
2. Arachchillage DRJ, Laffan M, Khanna S, et al. Frequency of Thrombocytopenia and Heparin-Induced Thrombocytopenia in Patients Receiving Extracorporeal Membrane Oxygenation Compared With Cardiopulmonary Bypass and the Limited Sensitivity of Pretest Probability Score. Crit Care Med. 2020;48(5):e371–e379. doi:10.1097/CCM.0000000000004261.
3. Argatroban. Micromedex Solutions. Greenwood Village, CO: Truven Health Analytics. Updated April 2 , 2020. Accessed April 6, 2020.
4. Attar D, Lines B, McCarty M, et al. Incidence of Heparin-induced Thrombocytopenia in Patients with Newly-implanted Mechanical Circulatory Support Devices. J Am Coll Cardiol. 2019 Mar, 73 (9 Supplement 1) 1212.
5. Balle CM, Jeppesen AN, Christensen S, Hvas AM. Platelet Function During Extracorporeal Membrane Oxygenation in Adult Patients: A Systematic Review. Front Cardiovasc Med. 2018;5:157. Published 2018 Nov 9. doi:10.3389/fcvm.2018.00157.
6. Berei TJ, Lillyblad MP, Wilson KJ, Garberich RF, Hryniewicz KM. Evaluation of Systemic Heparin Versus Bivalirudin in Adult Patients Supported by Extracorporeal Membrane Oxygenation. ASAIO J. 2018;64(5):623–629. doi:10.1097/MAT.000000000000069.
7. Bivalirudin. Micromedex Solutions. Greenwood Village, CO: Truven Health Analytics. Updated April 2, 2020. Accessed April 6, 2020.
8. Blum EC, Martz CR, Selektor Y, Nemeh H, Smith ZR, To L. Anticoagulation of Percutaneous Ventricular Assist Device Using Argatroban-Based Purge Solution: A Case Series. J Pharm Pract. 2018;31(5):514–518. doi:10.1177/0897190017727191.
9. Cuker A, Arepally GM, Chong BH, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia. Blood Adv. 2018;2(22):3360–3392. doi:10.1182/bloodadvances.2018024489.
10. Different Types of ECMO. University of Iowa Health Care. 2017. https://uihc.org/health-topics/different-types-ecmo.
11. Extracorporeal Life Support Organization.ECLS Registry Report. International Summary 2014 Jan.
12. Joseph L, Casanegra AI, Dhariwal M, et al. Bivalirudin for the treatment of patients with confirmed or suspected heparin-induced thrombocytopenia. J Thromb Haemost. 2014;12(7):1044–1053. doi:10.1111/jth.12592.
13. Koster A, Ljajikj E, Faraoni D. Traditional and non-traditional anticoagulation management during extracorporeal membrane oxygenation. Ann Cardiothorac Surg. 2019;8(1):129–136. doi:10.21037/acs.2018.07.03.
14. Lamarche Y, Cheung A, Ignaszewski A, et al. Comparative outcomes in cardiogenic shock patients managed with Impella microaxial pump or extracorporeal life support. J Thorac Cardiovasc Surg. 2011;142(1):60–65. doi:10.1016/j.jtcvs.2010.07.075.